Many types of machines has been set up in a semiconductor manufacturing factory and a liquid crystal display manufacturing factory. Several by-products will be formed in the semiconductor manufacturing process. When finishing the semiconductor manufacturing process, those by-products are remained in the machines so that the user needs to clean the by-products out of the machines periodically. Those by-products may be in forms of powder, crushed piece, and chunk. The user needs to maintain the machines for avoiding a particle defect of the products. The maintaining task is to draw the unuseful powder by a low vacuum system to keep the machines in a normal state. However, there are usually different by-products generated in different machines. For an example, a first machine is provided for depositing silicide and a second machine is provided for etching silicon nitride. When the first machine and the second machine are operated in a series of semiconductor manufacturing process, there are two different types of by-products .alpha. and .beta. remained in the first machine and the second machine respectively.
Please refer to FIGS. 1 to 3. When maintaining the machines A, B, C, D as shown in FIG. 3 (in fact, the total number of the machines in a manufacturing factory is above two hundred), the user needs to draw the by-products such as the powder individually by a low vacuum system 32. The user must plug the inlet 201 of the first low vacuum tube 20 in the socket 202 for drawing the by-products from the machines A, B, C, D through the socket 202 and the low vacuum tube 20. As shown in FIG. 2, the socket 202 has many sub-tubes 203 and two steel rods 204 secured cross to each other, and the by-product in machine A will be carried by the airflow generated from the low vacuum system 32 to flow through the second low vacuum tube 30 directly. At the present time, the low vacuum system 32 in a general manufacturing factory does not have a collecting device mounted in the socket 202 for filtering the airflow accompanied with the by-products so that there are always some by-products accumulated inside the low vacuum tube 30 during pumping.
Taking an example as shown in FIG. 2, there are four different kinds of by-products accumulated inside the surface of the second low vacuum tube 30 continuously, more especially in the connection 31 during pumping. Those by-products will react with each other to form new by-products or generate static electricity resulting in a fire originating from the connection 31. Those by-products can also reduce the useful life of the low vacuum system 32 and increase the maintaining cost of the factory.
In addition, it still has danger due to the improper treatment of the by-products. Every kind of by-product is accumulated continuously in the same spot so that they will react with each other to generate a poison gas. If someone inhales the poison gas, it will influence the health of the people. It is desired to develop a method to solve the problems encountered with the prior art.